Centralizer



p 4, 1965 J. c. CURTIS 3,206,259

CENTRALIZER Filed Aug. 10, 1961 2 Sheets-Sheet 1 FIG. I

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7 53 I W 8 2 -#50 minimum i ss INVENTOR J HN C. CURTIS BYZZ Sept. 4, 1965 J. c. cuRT1s 3,206,259

CENTRALIZER Filed Aug. 10, 1961 2 Sheets-Sheet 2 FIG.3.

@ INVENTORS JOHN C. CURTIS AGENT United States Patent 3,205,259 CENTRALIZER John C. Curtis, Newport, N.H., assignor to Joy Manufacturing Company, Pittsburgh, Pa, a corporation of Pennsylvania Filed Aug. 10, 1961, 32:. No. 130,555 3 Claims. (Cl. 308-33) This invention relates to improvements in drill steel centralizers.

The apparatus usually associated with this invention comprises an elongated guide frame having longitudinally extending guideways upon which a drill motor is reciprocably rectilinearly movable. The guide frame is so mounted that it is positionable in drilling alignment with either horizontally or vertically extending walls of solid rock. The formation of holes in the solid rock is accomplished by securing one end of an elongated shank or drill steel to the output of the drill motor and a drill bit to the other end of such drill steel. Coupling means having an internally threaded bore and a greater diameter than the steel shank are formed on one end of each steel to secure the steels to the drill bit and the motor. After the guide frame has been positioned adjacent a selected spot in the rock formation, drilling is initiated by actuating the drill motor, which transmits rotational or intermittent rotational and axial forces to the drill bit through the drill steel connected to such motor. Since it is usually desired that the holes be greater in depth than the length on one steel, additional steels are added thus comprising a drill string.

To insure proper operation of such apparatus means are invariably provided for guiding and supporting the drill steels during operation thereof. Such means are commonly referred to as a centralizer which is fixed or movably mounted on the guide frame. Such centralizers comprise arm portions having respective ends mounted for pivotal movement relative to the guide frame so that the arm portions are pivotal ina plane substantially perpendicular to the axis of the drill steels. The other end portion of the arms have, respectively, semi-circular openings which when in abutting adjacency form a circular bearing through which the drill is supported and guided. Due to the fact that the couplings are of greater diameter than the drill steels the centralizer must be opened and closed to allow passage of the coupling past the centralizer.

Assuming a hole has been drilled to the depth of three steels and it is desired to uncouple the drill stem under such circumstances the drill motor is retracted to its starting position on the guide frame thus pulling the entire drill string with it. Before this, however, the centralizer is opened by hand to allow clearance for the coupling to traverse the centralizer. The centralizer is then closed and the drill motor is moved along the guide frame until the coupling rests on the centralizer. The drill motor is reversibly rotated to uncouple the steel positioned between the output shaft of the drill motor and the centralizer. The steel so uncoupled is moved to a remote location and the drill motor is moved along the guide frame toward the centralizer. Proper actuation of the drill motor causes its output shaft to become connected to the coupling resting on the centralizer. The drill motor is again moved along the guide frame to the starting position and the operation is repeated until all the steels are so uncoupled.

The structure of this invention eliminates the necessity of requiring the operator of a drilling apparatus to open the centralizer during the uncouplingof drill steels.

The invention discloses a structural combination which facilitates the uncoupling of drill steels by permitting the 3,206,259 Patented Sept. 14, 1965 ice centralizer to be automatically opened and closed when drill steel couplings traverse the centralizer.

Accordingly one object of this invention is to provide a new and improved centralizer.

Another object of this invention is to provide a new and improved drill steel centralizer which is operable to reduce the effort and time for uncoupling drill steels.

A more specific object of this invention is to provide a new and improved drill steel centralizer which is automatically opened by a drill steel coupling during retraction of such drill steel.

An additional object of this invention is to provide a new and improved drill steel centralizer which is automatically positioned to support a drill string during uncoupling thereof.

These and other objects and advantages of the invention will become more apparent when taken in conjunction with the following drawings, in which:

FIG. 1 is the front view of the drill steel centralizer constructed according to the principles of this invention showing the arm portions in closed position;

FIG. 2 shows the arm portions in opened position;

FIG. 3 shows the arm portions being opened by a coupling when the drill steel is being withdrawn from the hole;

FIG. 4 shows the arm portions of the centralizer assembly supporting the drill strin g.

Referring now to FIGS. 1 to 4 which show, respectively, an exploded perspective view of a drill steel centralizer constructed according to the principles of this invention and the centralizer mounted on a suitable drilling apparatus. One form of drilling apparatus to which the centralizer is applicable comprises an elongated guide frame formed by spaced elongated channel members 20 which support and rectilinearly guide a drill motor and associated drill steels S. Means, such as a feed motor, are mounted on a guide frame for bodily moving the drill motor and the drill steels along the guide frame channel members 29.

Rectangular plates are suitably secured to the inner periphery of the channel members 20 and extend laterally inwardly toward each other. A laterally disposed rectangular plate 26 is secured to the guide frame channel members 20 by suitable bolts 24 which extend through the plates 22 and the plate 26. Suitably rigidly secured to the plate 26 as shown, are stepped blocks 28 which are oriented so that the stepped portion thereof extend in the same directions. A rectangular plate 30 disposed parallel to the plate 26 and extending between the blocks 28 has the end portions thereof rigidly abuttingly secured to the inner surface of the blocks 28 respectively. Another rectangular plate 31 being substantially transversely coextensive with the plate 26 is suitably rigidly secured to the stepped blocks 28, plate 26, and plate 30 to form a rigid b'oxlike frame.

Spaced inwardly from the blocks 28 respectively and having adjacent end portions suitably rigidly secured to plates 26, 30 and 31 are supporting gusset members 32. It will be noted that the end portions of members 32 secured to and abutting the plate 30 are equal in width to the width of plate 30.

The blocks 28 have step portions 33 and 38 respectively. The end face of step 33 locates, hereinafter described, centralizer arms 48 so that they are movable in a common plane. Holes 34, extending from the end face of step 33, respectively, through the blocks 28 respectively, and through the plate 31, are provided for slidably receiving elongated bolts 36 whose smooth shank portion extends beyond the face 33 with the head portion thereof being abuttingly engaged with the plate 31. The step portions 38 extend beyond the face 33 and include respectively, longitudinally extending inwardly inclined sur- 'to the centralizer support.

faces 40 and a surface 39 whose purpose will be specified in connection with the centralizer arms 48.

Formed stop members 42 located coplanar with and rigidly secured to gusset members 32 and plate 30 respectively, are provided. The members 42 include, respectively, elongated laterally aligned slots 46 and a rearwardly extending tapered portion 44 secured to the lower surface of plate 3'9. The members 42 provide surfaces 47 which are abuttingly engageable by hereinafter described arms 48 to limit the inward movement of the arms The above described structure comprises a support for the arm members 48. Since the arms 48 are of identical construction the following description will be confined to one arm. The arm 48 is formed with an end portion 50 having on the upper surface thereof, an integral protruding portion 52 extending laterally outwardly thereof and such portion 52 includes a lower flat surface 53. The lower surface of the end portion 50 has an integrally formed clevis member comprising aligned and spaced elongated lever portions 54. Axially aligned holes 62 are formed in the levers 54. The end portions 50 have a hole 58 with a bushing 60 suitably rigidly disposed therein through which the shank of bolt 36 is slidably fitted.

The remaining end portion of arm 48 has a semi-annular portion 64 having the axis thereof extending substantially normal to the axis of hole 58. The inner surface 68 of portion 64 has a groove 68 of generally rectangular cross section for positioning a suitable bushing half 70. The bushing half 7 6 has formed on the outer surface thereof an enlarged portion 72 which is coplanar and complementary with the groove so that the half bushing 70 is positionable in a predetermined longitudinal position relative to the tubular portion 64. Suitable screws 74 for retaining the bushing half 79 in the position shown are provided with the threaded portion being in engagement with a cooperating threaded hole formed in the bushing half 70.

Means are provided for biasing the arms 48 in a closed or open position. Such means comprise an elongated tubular member 80 having cylindrical plungers 82 arranged at both ends of the member 80 to be axially movable in the bore of member 80. As shown, the exterior end portions of the plungers 82 respectively have diametrically opposed flat portions 84 and a hole 86 formed therethrough whose axis is normal to the flat portions 84. As shown in FIGS. 2 and 3 a coil spring 88 is slidably disposed in a tubular member 80 with the ends of the cylindrical plungers 82 in abutting engagement therewith. Such an arrangement causes the spring to be compressed when the plungers are moved toward each other in the member 80.

Vlhen assembled the bolts 36 are disposed in the holes 34 with the shank portion thereof extending a suitable distance from the face 33 to extend through and beyond the holes in the respective bushings 60. By disposing a suitable washer and nut 76 and 78 respectively, on the bolts 36 respectively the arms 48 are then pivotably secured The respective end portions of the plungers 82 are then disposed between the levers 54 respectively thus forming a close connection. A suitable pin pivotally secures the plungers in this position.

The centralizer of this invention operates in the following manner. Assuming the drilling apparatus is positioned to drill a generally vertical downward hole it will be appreciated that in the position of FIG. 1 a turning moment on the left and right hand arms 48 is applied clockwise and counterclockwise respectively by the weight of the arms 48 and by the action of the spring 88 against the plungers 82. The arms 48 are maintained in this position by the respective portions thereof which are abuttingly engaged with the surface 47. In this position the turning moment due to the weight of the arms 48 and the force applied by the spring 88 acts in the same direction thus cooperating forcibly to maintain the arms 48 in the position shown in FIG. 1. As the coupling C aproaches the portions 64 the arms 48 are manually rotated about the axis of the bolts 36 until the surface 53 on the stop member 52 is in abutting engagement with the surface 39 on the block member 28. This position is maintained due to the action of the spring 88 against the plungers 82 which apply a clockwise moment on the right hand arm 48 and a counterclockwise moment on the left hand arm 48. After the coupling has passed the position occupied by the bushing 7t) the arms are manually rotated to the position shown in FIG. 1.

During the uncoupling of the drill steels S the centralizer operates in the following manner. After the hole has reached the desired depth the drill string is removed from the hole by disconnecting the coupled drill steels. The drill motor is retracted upwardly along the guide frame members 20 to its starting position and in so moving the entire drill string which is attached to the motor is also moved. In so moving, the uppermost coupling, as shown in FIG. 3, causes the centralizer arms 48 to be rotated outwardly due to the fact that the diameter of the coupling is substantially greater than the inner diameter of the bushing halves 70. Continued movement of the drill string causes the coupling C to move past the centralizer arms 48. The weight of the arms 48 and the force of the spring 88 act to rotate the arms inwardly to the position shown in FIG. 5. The drill string is suspended in this position by resting the coupling on the bushing portion 70 of the centralizer arms. Means, which are conventional in the art, is connected to hold the drill steel against rotation. The drill motor is then reversed to uncouple the drill steel disposed between the drill motor and the centralizer arms 48. The uncoupled steel is removed to a remote storage location. The drill motor is moved downwardly along the guide frame members 20 adjacent the coupling supported by the arms 48 and the drill motor is rotated to connect its output shaft to such coupling. Retraction of the drill upwardly along the guide frame members 26 positions another drill steel for uncoupling. drill steels are uncoupled.

Having described a preferred embodiment of this invention in accordance with the patent statues it is to be realized that modifications thereof may be made without departing from the broad spirit and scope of the appended claims. Accordingly it is respectfully requested that this invention be interpreted as broadly as possible and be limited only by the prior art.

What is claimed is:

1. A drill steel centralizer adapted to support a substantially vertical string of coupled drill steels during uncoupling thereof comprising, a support, said support having spaced pivot means secured thereto, drill steel guide means including arm members each having at one end thereof a portion pivotally connected to said pivot means for permitting arcuate movement of said members respectively in opposite directions, toward and away from each other about said respective pivot means, in a plane containing the axis of such steels, a drill steel guide portion on the other end of said arm members respectively, said drill steel guide portion including a portion of a size adapted only to embrace the drill steel for guiding the latter during rectilinear movement thereof and another portion of a size adapted only to have contact with the end portions respectively of the coupling elements of said drill string, the size of said guide portion which embraces said drill steel bein of a smaller size than the couplings so that passage of such couplings past said drill steel guide portion is obstructed, said arm members being pivotally moved away from each other out of their drill steel guiding positions by the coupling elements during extraction of such drill steels, means for moving said arm members toward each other as such coupling elements traverse the position occupied by said guide portions of said arm members, said last mentioned means including an elongated This operation is repeated, until all the tubular member having a spring disposed interiorly thereof and plungers slidably disposed in said tubular member with respective ends thereof in abutting engagement with said spring, and means pivotally connecting the other ends of said plungers to said arm members respectively adjacent the pivotal connections of said arm members to said support.

2. A drill steel centralizer as set forth in claim 1 Wherein the means for pivotally connecting the other ends of said plungers to said arm members respectively includes inwardly directed lever portions formed integrally with said arm members respectively and having a pivot connection at their outer ends for pivotally connecting said lever portions to said plungers, said last mentioned pivot connections being located with respect to said pivot means for said arm members below a straight line connecting said spaced pivot means for said arm members when said arm members are in their inward or drill steel guiding position, stop members on said support abuttingly engaged by said arm members for limiting the inward movement of said arm members, the force of said spring when said pivot connection of said lever portions to said plungers are so located below said straight line forcibly maintaining said arm members inwardly against said stop members irrespective of the weight of said arm members.

References Cited by the Examiner UNITED STATES PATENTS 448,698 3/91 Turner 200-67 877,572 1/08 Larsson -200 1,317,382 9/19 Newton 200-67 1,481,378 1/24 Le Bus 175-200 1,485,308 2/24 Stegeman 175-200 2,308,203 7/40 Farrell 308-39 2,483,122 9/49 Bower 200-67 2,675,997 4/54 Osgood 308-39 2,976,943 3/61 Curtis 175-223 ROBERT C. RIORDON, Primary Examiner.

CHARLES OCONNELL, Examiner. 

1. A DRILL STEEL CENTRALIZER ADAPTED TO SUPPORT A SUBSTANTIALLY VERTICAL STRING OF COUPLED DRILL STEELS DURING UNCOUPLING THEREOF COMPRISING, A SUPPORT, SAID SUPPORT HAVING SPACED PIVOT MEANS SECURED THERETO, DRILL STEEL GUIDE MEANS INCLUDING ARM MEMBERS EACH HAVING AT ONE END THEREOF A PORTION PIVOTALLY CONNECTED TO SAID PIVOT MEANS FOR PERMITTING ARCUATE MOVEMENT OF SAID MEMBERS RESPECTIVELY IN OPPOSITE DIRECTIONS, TOWARD AND AWAY FROM EACH OTHER ABOUT SAID RESPECTIVE PIVOT MEANS, IN A PLANE CONTAINING THE AXIS OF SUCH STEELS, A DRILL STEEL GUIDE PORTION ON THE OTHER END OF SAID ARM MEMBERS RESPECTIVELY, SAID DRILL STEEL GUIDE PORTION INCLUDING A PORTION OF A SIZE ADAPTED ONLY TO EMBRACE THE DRILL STEEL FOR GUIDING THE LATTER DURING RECTILINEAR MOVEMENT THEREOF AND ANOTHER PORTION OF A SIZE ADAPTED ONLY TO HAVE CONTACT WITH THE END PORTIONS RESPECTIVELY OF THE COUPLING ELEMENTS OF SAID DRILL STRING, THE SIZE OF SAID GUIDE PORTION WHICH EMBRACES SAID DRILL STEEL BEING OF A SMALLER SIZE THAN THE COUPLINGS SO THAT PASSAGE OF SUCH COUPLINGS PAST SAID DRILL STEEL GUIDE PORTION IS OBSTRUCTED, SAID ARM MEMBES BEING PIVOTALLY MOVED AWAY FROM EACH OTHER BUT OF THEIR DRILL STEEL GUIDING POSITIONS BY THE COUPLING ELEMENTS DURING EXTRACTION OF SUCH DRILL STEELS, MEANS FOR MOVING SAID ARMS MEMBERS TOWARD EACH OTHER AS SUCH COUPLING ELEMENTS TRAVERSE THE POSITION OCCUPIED BY SAID GUIDE PORTIONS OF SAID ARM MEMBERS, SAID LAST MENTIONED MEANS INCLUDING AN ELONGATED TUBULAR MEMBER HAVING A SPRING DISPOSED INTERIORLY THEREOF AND PLUNGERS SLIDABLY DISPOSED IN SAID TUBULAR MEMBER WITH RESPECTIVE ENDS THEREOF IN ABUTTING ENGAGEMENT WITH SAID SPRING, AND MEANS PIVOTALLY CONNECTING THE OTHER ENDS OF SAID PLUNGERS TO SAID ARM MEMBERS RESPECTIVELY ADJACENT THE PIVOTAL CONNECTIONS OF SAID ARM MEMBERS TO SAID SUPPORT. 